Background:

Previous studies have shown an association between living alone and cancer mortality; however, findings by sex and race/ethnicity have generally been inconsistent, and data by socioeconomic status are sparse. The association between living alone and cancer mortality by sex, race/ethnicity, and socioeconomic status in a nationally representative US cohort was examined.

Methods:

Pooled 1998-2019 data for adults aged 18-64 years at enrollment from the National Health Interview Survey linked to the National Death Index (N = 473,648) with up to 22 years of follow-up were used to calculate hazard ratios (HRs) for the association between living alone and cancer mortality.

Results:

Compared to adults living with others, adults living alone were at a higher risk of cancer death in the age-adjusted model (HR, 1.32; 95% CI, 1.25-1.39) and after additional adjustments for multiple sociodemographic characteristics and cancer risk factors (HR, 1.10; 95% CI, 1.04-1.16). Age-adjusted models stratified by sex, poverty level, and educational attainment showed similar associations between living alone and cancer mortality, but the association was stronger among non-Hispanic White adults (HR, 1.33; 95% CI, 1.25-1.42) than non-Hispanic Black adults (HR, 1.18; 95% CI, 1.05-1.32; p value for difference < .05) and did not exist in other racial/ethnic groups. These associations were attenuated but persisted in fully adjusted models among men (HR, 1.13; 95% CI, 1.05-1.23), women (HR, 1.09; 95% CI, 1.01-1.18), non-Hispanic White adults (HR, 1.13; 95% CI, 1.05-1.20), and adults with a college degree (HR, 1.22; 95% CI, 1.07-1.39).

Conclusions:

In this nationally representative study in the United States, adults living alone were at a higher risk of cancer death in several sociodemographic groups.